Montgomeby waddell



(No Model.)

M. WADDELL.

METHOD OF BLASTING. No. 386,281, Patented July 1'7, 1888.

N PETERS, PhoioLhhngr-mpher, Wilhinglcfl, u. C.

PATENT OF ICE.

MONTGOMERY WADDELL, OF NEW YORK, N. Y.

METHOD OF BLASTING.

SPECIFICATION forming part of Letters Patent No. 386,281, dated July 17,1888. Application filed January 13, 1888. Serial No. 260,645. (Nomodel.)

To aZZ whom it may concern.-

Be it known that I, MONTGOMERY WAD- DELL, a subject of the Queen ofGreat Britain, residingat New York city, in the county ofNew York andState of New York, have invented a certain new and useful Improvement inBlasting, of which the following is a specification.

The object of my invention is to provide a method of separating orblasting rock, coal, or similar materials, in mines or elsewhere, whichshall be simple, cheap, and effective in operation, and shall also avoidthe danger arising from the use of explosives. In accom plishing this Ibore or drill in the usual manner into the rock or material to beoperated upon, and I fill the bottom of the hole thus formed with asemi-electrical conducting material, such as powdered charcoal, charcoaland water, or other high-resistance material which will expand whenheated. I then insert in the hole, so that their extremities enter thebody of charcoal or other material, two

metal rods,whose outer ends are provided with means for connecting themwith conductors leading from asource of electricity. The hole is thentamped or filled in in the usual manner in blasting, and so that therods remain separated throughout their length. On current from saidsource being passed through the circuit thus formed the high resistanceoffered by the semi-conducting material resultsin the generation of heattherein, and the consequent expansion is such as to cause the breakingor disruption of the rock or other material which surrounds it. In somecases I may employ water or other liquid which will be decomposed by thepassage of the current, so that the expansion of the gases will causethe desired effect. I usually prefer, however, to depend on the effectof heat and to employ such a material as will be heated and expand bythe current. In any case I employ a non-explosivc material, by which Imean one which does not explode when the current is passed through it. Imay employ either a continuous or an alternating current. I may inpractice first send a weak current through the circuit in order to startthe action, and then quickly increase it to cause the disruption.

In the accompanying drawing, which is a sectional view of theblasting-aperture, A is the drilled hole, which at its lower end isfilled with charcoal or other suitable material, B.

G G are the metal rods, placed in the hole with their ends entering thematerial B. Such rods may be jointed, their ends being separable at a a,so that if they are injured by the operation new end pieces may besubstituted. Above the chargeis placed the filling or tamping material,D, in the usual manner. A disk, E, of non-conducting material, may beemployedto separate the rods. The upper ends of the rods are providedwith bindingposts F, for connecting them with an electrical circuit.Such circuit is shown as extending from a dynamoelectric machine, G,which is provided with a regulating resistance, H, whereby the currentsupplied may be varied.

The operation of this apparatus is as al ready explained.

What I claim is- 1. The method of separating rock and like material,consisting in confining a non-explosive electrical conducting bodywithin the mass of material to be acted upon, passing an 1 electriccurrent through said confined body, and thereby causing disruption ofthe material by the expansion of the confined body without exploding thesame, substantially as set forth.

2. The method of separating rock and like material, which consists inboring a hole therein, placing in said hole an electrical con ductingmaterial, tamping the hole above said material, and passing an electriccurrent through such material, so thatthesame is made to expand and todisrupt the rock by such expansion, substantially as set forth.

3. The method of separating rock and like material, which consists inboring a hole therein, placing in said hole an electrical conductingmaterial of high resistance, tamping the hole above said material, andpassing an electric current through such material, so that 9 the same ismade to expand and to disrupt the rock by such expansion, substantiallyas set forth.

4. The method of separating rock and like material, which consists inboring a hole This specification signed and witnessed this 11th day ofJanuary, 1888.

MONTGOMERY WADDELL. V

l/Vitnesses: l WILLIAM PELZER,

E. O. ROWLAND.

therein, placing in said hole an electrical conducting material of highresistance, inserting in said material the ends of electricalconductors, filling theholewith tamping material, 5 so as to separatesaid conductors, and passing an electric current through saidconductors, substantially as set forth. 1

